Most projects fail. It’s not always because the idea is flawed or the people are wrong – but because the thinking is.
Bent Flyvbjerg and Dan Gardner, authors of How Big Things Get Done (Financial Times’ 2023 Business Book of the Year), spent decades studying why major projects crash – and what the outliers got right. Their conclusion? Heuristics – simple mental rules used by expert builders, filmmakers, architects, and visionaries, among others, to guide big decisions.
This post covers Flyvbjerg/Gardner’s mental frameworks – each one a mental model, method, principle, or virtue – to help you plan smarter, move faster, and lead with clarity when the stakes are high.
1. Hire an Experienced Builder
Principle Model: Choose someone with deep experience and a record of success.
Big projects die by committee. The best ones – from Pixar films to Apple – succeed because one experienced builder leads with vision and authority. Flyvbjerg/Gardner:
“Most big projects are not the first, tallest, biggest… They are relatively normal highways and rail lines, office buildings, software, hardware, movies, home renovations, (etc). People don’t expect them to be grand cultural landmarks. They want them to finish on budget and on time, do what they’re supposed to, do it well and reliably, and do it for a long time. For such projects, experience can help enormously. If there is a design – or a system, process, or technique – that has delivered many times before, use it, or tweak it, or mix-and-match it with similarly proven designs. Use off-the-shelf technologies. Hire experienced people. Rely on the reliable. Don’t be the first.”
This isn’t about credentials. It’s about phronesis (Greek word for wisdom) – practical wisdom earned through repeated wins. A master builder doesn’t just lead, they assemble the right systems and people to get it done. Most importantly, the build master should be able to assemble a master team.
2. Choose a Winning Team
Mental Method: Design your collaboration system, not just your org chart.
You don’t superstars – you need synergy. The team is the product. As the authors highlight, this heuristic is the only one consistently highlighted be project leaders. Quoting Pixar co-founder and President of Disney Animation, Ed Catmull:
“Give a good idea to a mediocre team, and they will screw it up. Give a mediocre idea to a great team, and they will either fix it or come up with something better. If you get the team right, chances are they will get the ideas right.”
3. Ask “WHY?”
Mental Model: Use First Principles thinking to clarify the goal.
If you don’t ask “why?”, you risk building something irrelevant – or harmful. Asking “why” uncovers the deeper purpose behind the project. As Flyvbjerg/Gardner write:
“Developing a clear, informed understanding of what the goal is and why – and never losing sight of it from beginning to end – is the foundation of a successful project.” (This can be done using the following tools):
Flow Chart: “In project planning, a standard tool is a flowchart that lays out, from left to right, what needs to be done and when, with the project
concluding when the goal is achieve in the final box on the right. This concept is also valuable in the initial planning stages because it can help us visualize a project not as an end in itself but as a means to an end: the goal is the box on the right. (Similarly, “Backcasting” is used in urban and environmental planning)”:
Backcasting: “Backcasting starts by developing a detailed description of a desirable future state; then you work backwards to tease out what needs to happen for that imagined future to become reality.”
Backcasting in particular isn’t a new concept. The ancient Stoics called it premeditatio malorum (preparing for what could go wrong). As noted in The Practice of Negative Visualization, this technique wasn’t about fear – it was about foresight. Annie Duke’s Thinking in Bets frames backcasting as a decision tool: start with your goal, and then work backwards as you identify key choices, assumptions, and risks. Likewise, Charlie Munger was inspired by Inversion, based on the same idea. As he often quoted, “invert, always invert” believing avoiding failure was more important than focusing on success.
The lesson? Asking WHY helps you clarify purpose. Backcasting, premeditatio malorum, and inversion help you pressure test the path before you begin.
4. Build with Lego
Mental Model: Break projects into modular, repeatable units — start small!
Don’t focus on building the cathedral. Builds bricks – and piecing them together. As the Flyvbjerg/Gardner argue, modular projects finish faster, scale better, and adapt easier or “Big is best build from small.” As they further write,
“Modularity is a clunky word for the elegant idea of big things made from small things… A brick wall is made of hundreds of bricks. A flock of starling may be composed of hundred of birds… The core of modularity is repetition. Repetition is the genius of modularity; it enables experimentation. Repetition also generates experience, making your performance better. Repetition rockets you up the learning curve, making each new iteration better, easier, cheaper, and faster.”
Build small, reusable systems. Then combine them with agility. This approach protects your project from scope creep, bottlenecks, and chaos.
5. Think Slow, Act Fast
Principle/Mental Model: Delay action until your plan is bulletproof.
Fast planning creates slow disasters. Slow planning helps speed up execution. “Measure twice, cut once” isn’t just carpentry – it’s a life strategy.
Slow planning isn’t just safer – it’s essential. Solving complex problems, testing ideas, and refining strategy takes deep thinking. And deep thinking takes time. Real creativity and critical planning can’t be rushed – they demand patience and deliberate focus. As the authors note, “The right approach for big projects: Put enormous care and effort into planning to ensure that delivery is smooth and swift. Think slow, act fast: That’s the secret to success.”
Solve hard problems first. Rehearse. Test. Prepare. Then execute like a sprinter.
Deep thinking takes time – and real creativity can’t be rushed. As Caesar Augustus proclaimed, “Festina lente” – Make haste slowly.
6. Take the Outside View
Mental Model: Use anchors (base rates) to escape optimism bias.
We’re wired for overconfidence. Nobel Prize winning economist/psychologist, Daniel Kahneman, calls it WYSIATI: What You See Is All There Is. We ignore what we don’t know. The solution: Take the outside view. Flyvbjerg/Gardner coined this method “reference-class forecasting”:
“Start with a different perspective: see your project as one in a class of similar projects already done. Use data from those projects – about cost, time, benefits, or whatever else you want to forecast – as your anchor. Then adjust up or down, if necessary, to reflect how your specific project differs from the mean in the class. That’s it.”
Don’t guess. Instead, anchor your plans to what is typical for your project. How does this concept work in reality? Again, the authors explain using a kitchen renovation as an anecdote:
“Look around for others who have done a kitchen renovation in, say, the past five to ten years. Ask friends, family, and co-workers. Kitchen renovations are common, so let’s say you come up with fifteen such projects. Get the total cost of each, add them, divide by fifteen. That’s your anchor.”
7. Watch Your Downside
Virtue Model: Plan for rare events that can destroy everything.
Most projects don’t fail because of predictable mistakes – they’re derailed by fat-tail events: rare but extreme disruptions.
Things will go wrong. Often in ways you didn’t expect. This heuristic is about respecting reality. Most big projects are fat-tailed — meaning that rare, high-impact disasters happen more often than expected. A fat-tail (termed “black swans” by author and mathematician, Nassim Taleb) event is a statistically rare event with extreme outcomes; one that causes outsized damage. As the authors write:
“All projects are vulnerable to unpredictable shocks, with their vulnerability growing as time passes. So the fact that the delivery of your one huge thing will take a very long time means that it is at high risk of being walloped by something you cannot possibly anticipate.”
For example, in fat-tailed systems – like IT projects, Olympic Games, or infrastructure builds – a single misstep can easily lead to 400%(+) cost overruns or outright failure. Every day your project drags on, you increase the chances of a “black swan” hitting, such as a pandemic, recession, political or legal changes. To prepare for black swans, build in contingency plans not just for delays, but for disasters. It’s also important to determine in advance when you’ll pause, pivot, or walk away from a project. Look for clarity in the Outside View.
8. Say No and Walk Away
Virtue Model: Cultivate courage and clarity under pressure.
Some of the most successful builders made their mark by walking away. Why? Because bad deals, failed ideas, or toxic partnerships will always cost more in the end. Before you begin, ask: Do we have the right people, the funding, the right contingencies? If not, walk away. If a task doesn’t directly serve the project’s core goals – skip it. Say not to vanity projects, unproven tech, and distractions that invite risk without value.
Even Steve Jobs once famously stated: “I’m actually as proud of the things we haven’t done as the things we have done.”
9. Make Friends and Keep Them Friendly
Daily Routine: Build relational momentum, one conversation at a time.
Big projects are built on goodwill. Contractors, suppliers, officials – they don’t have to help you, but they will if they like you. Flyvbjerg and Garner point out that relationships are your risk management. They write: “If something goes wrong, the project’s fates depends on the strength of those relationships. And when something goes wrong, it’s too late to start developing and cultivating them. Build your bridges before you need them.”
10. Know That Your Biggest Risk Is You
Mental Model: Defuse the planning fallacy and your own ego.
Your confidence will lie to you, your memory will betray you, and your vision will outrun your discipline. The number one cause of project failure is overconfidence – especially at the top. This is where humility meets cognition. Know that your greatest risk isn’t the budget or timeline. It’s you. So build safeguards accordingly.
To challenge this notion: Try adding friction to your decision-making. invite opposing, disconfirming views. Stay humble.
Final Thought:
Flyvbjerg and Gardner’s heuristics are more than project advice – they’re thinking systems. Use them to plan accordingly, move deliberately, and lead well.
Because big things don’t get done by accident. Things get done by thinking better.